There are many known control systems, such as for controlling and setting vehicle speed for an agricultural or industrial utility vehicle, such as tractors, harvesting machines, combine harvesters, forage harvesters, self-propelled sprayers, construction vehicles, bulldozers, graders, backhoe excavators, loading vehicles, tipper trucks, cranes and telescopic loaders.
Moreover, force-feedback is known from the field of simulator technology and is generally used for the realistic representation of forces on operating elements, which occur during the operation of a real machine and have to be applied and/or overcome by the operator. In this case, an adjusting device and/or an actuator is provided, by means of which at least one operating element may be acted upon by a force. As a result, the operating element which merely generates an electrical signal about its operating state, may be acted upon by the adjusting device with a corresponding force, so that the operating element has an operating characteristic which is conventional for the type of respective operating element.
In many vehicles, the operating elements are mechanically connected to a machine part. For example, the steering wheel is connected by a steering shaft to the steering gear. If such a mechanical connection is omitted due to an electronic control of the respective component, a corresponding feedback about the conditions of the machine part and the machine/vehicle to be simulated is not provided to the operator. In such a case, the technology known from simulator technology is utilized, namely by the operating element or pedal being acted upon by forces using an adjusting device, which is controlled by a suitable control unit, such that a conventional operating characteristic for the operating element may be produced. As a result, an operation of the respective function controlled by the operating element which is as realistic as possible is simulated to an operator.
Extensive assistance during the operation of a utility vehicle is, however, made known to the operator visually or possibly acoustically by warning display elements. In this case, primarily warning lights are provided which indicate a critical state of the utility vehicle, for example that of an excessive temperature of the engine oil or of the coolant above a predetermined upper threshold.